1. Field of the Invention
The invention relates to testing apparatus; and, more particularly, to apparatus for detecting the amount of air present in a previously pressurized container. Other gases are also detected.
2. Description of the Prior Art
Normally, in a wine packaging process, an assembly line is used to move a plurality of empty wine bottles past stations where they are filled with wine, then to a corking station where corks are placed in the open bottle tops to seal the same. Prior to such corking, the liquid contents of the bottle are depressurized to remove all air or gases from the bottle which air is detrimental both to the quality of the wine and the efficiency of the seal. High quality wineries desire to have no air at all present in their wines after corking. In addition to the quality of the wine, there has been an increase in leakage and accidents caused by bottles exploding after pressurizing and corking due to residual pressurized gases being present in the bottles where it was thought there were no gases. The bottles would thus break, leak and, when inverted, pressure would drive the wine out of the bottle or force a passageway to open slowly in the side of the cork since the cork is fresh and hadn't yet hardened. Such air, being present in the wine, even if pressurized, will affect the quality of the wine.
In order to check on the quality of the vacuum process, which step is carried out almost instantaneously prior to corking, various techniques have been suggested to determine if the right amount of vacuum is being pulled from the bottles. For example, in one technique, an empty bottle is run through the vacuum forming process and corked without any liquids contents therein. If the vacuum forming apparatus has a plurality of different vacuum-forming heads, which can clog up due to cork dust or the like, empty bottles must be tested for each head. This of course is quite time consuming and cannot be done manually since it is difficult to pierce a cork with a needle or the like manually. Also, the needle must be large enough to be easily inserted (which large sized needle might collapse or otherwise break the cork) yet not too delicate or it will break.
Various prior art devices, such as those disclosed in U.S. Pat. Nos. 1,211,942; 4,208,903 and 1,539,937 have been suggested in the past but have proven unsatisfactory for use in today's assembly line filling techniques. For example, in U.S. Pat. No. 4,208,903, the complicated machine actually shakes a heavily carbonated liquid since it is desired to measure the degree of carbonization, directly opposite of what is desired in the wine industry.
There is thus a need for apparatus for quickly and easily determining if there is any air present in a previously pressurized corked liquid-containing bottle.
The term air as used herein is intended to include all of the gases that may be present in a bottle of wine, champagne or sparkling wine, namely CO.sub.2, N.sub.2, O.sub.2 and the like.